SHOULD ALL PATIENTS WITH DILATED CARDIOMYOPATHY RECEIVE CHRONIC ANTICOAGULATION

OBJECTIVE: To review the mechanism of intracardiac thrombus formation, describe the risk of systemic thromboembolization, critically evaluat e the literature regarding the use of oral anticoagulation, review the American College of Chest Physicians (ACCP) guidelines, and provide r ecommendations for oral anticoagulation in patients with dilated cardi omyopathy (DCM). DATA SOURCES: English language clinical studies, abst racts, and review articles pertaining to oral anticoagulation and DCM. STUDY SELECTION AND DATA EXTRACTION: Relevant human studies examining the role of anticoagulation for preventing systemic thromboembolism i n patients with DCM. DATA SYNTHESIS: Potential mechanisms and risk fac tors for systemic thromboembolization in patients with DCM are discuss ed. Studies evaluating the benefits and risks of chronic oral anticoag ulation to prevent systemic thromboembolization are critiqued. Recomme ndations for oral anticoagulation in patients with DCM from the second and third ACCP Consensus Conferences are reviewed. Suggestions for st udy design of a new clinical trial are presented. CONCLUSIONS: The sec ond ACCP Consensus Conference recommended chronic anticoagulation for all patients with DCM, but the third conference did not address this i ssue. Review of demographic data from clinical trials demonstrates rel uctance to use anticoagulation in all patients with DCM because of lac k of support from prospective, controlled trials. Recent data from lar ge clinical trials suggest that the risk of systemic embolization may be lower than previously believed. We recommend the use of chronic ant icoagulation with warfarin in patients for whom the risk of embolism i s greater than the risk of major bleeding, such as those with atrial f ibrillation or previous systemic embolization. Lack of compliance with ACCP guidelines suggests that clinicians require additional informati on regarding the bleeding risk and systemic embolization rate reductio n of chronic anticoagulation in patients with DCM who remain in normal sinus rhythm. It is only through prospective, controlled trials that this risk/benefit ratio to prevent systemic embolism in patients with DCM can be established.